For the alleviation of the side effect of drugs, there have been proposed pharmaceutical compositions comprising a drug and a carrier or the like. As an example, non-steroidal anti-inflammatory agents show a strong anti-inflammatory action to inflamation-affected parts, but they are known to give serious side effects to the central nervous system and the digestive system and to cause hemorrhage and ulcer in the digestive system, in particular; in order to alleviate these side effects, there was proposed, for example, a pharmaceutical composition comprising a non-steroidal anti-inflammatory agent or a salt thereof and 0.2-50 parts by weight, based on 1 part by weight of the former, of salicylic acid and/or an alkali metal salicylate as an activating agent [Japanese Patent Application Kokai (Laid-Open) No. 82715/1976). Further, it was proposed to include Indometacin, a non-steroidal anti-inflammatory agent in a biodegradable carrier selected from collagen and gelatin (Japanese Patent Application Kokai (Laid-Open) No. 84213/1985), or to include Indometacin in cyclodextrin to enable the sustained release of Indometacin (Japanese Patent Application Kokai (Laid-Open) Nos. 62313/1979 and 117018/1979). Furthermore, there was proposed in Japanese Patent Application Kokai (Laid-Open) No. 110334/1979 a method wherein Indometacin is mixed with a benzodiazepine compound to thereby reduce the administration amount of Indometacin and to inhibit the expression of its serious side effect.
Though these conventional methods are superior in sustained release of drug, they are poor in absorption of drug into human body, take a long time before the drug exhibits an anti-inflammatory action, and hardly show sufficient effects for the alleviation of the side effect of the drug to the digestive system.
There were also proposed pharmaceutical compositions using albumin as a carrier, such as a composite of a 5-fluorouracil derivative and albumin [Japanese Patent Application Kokai (Laid-Open) No. 151988/1979) and a drug-albumin composite of sustained release type (Japanese Patent Application Kokai (Laid-Open) No. 162595/1983). These pharmaceutical compositions using albumin as a carrier described in the above patent documents, however, have drawbacks in that in their preparation, the binding property of the carrier albumin must be improved in advance at a pH of 6-11 at a temperature of 30.degree. C. or below using a cyanogen halide or a perhalogenic acid, or the affinity of the carrier albumin must be improved in advance using a spacer of a functional compound or the like, thus requiring many preparation steps and making the preparation procedure complex.
The present invention has been made in order to solve the above-mentioned problems of prior arts. The first object of the present invention is to provide a pharmaceutical composition which can alleviate the side effect of the drug contained therein to the skin and mucous membrane, particularly the digestive system and can improve the absorption, light stability, etc. of the drug. The second object of the present invention is to provide a process which can produce a pharmaceutical composition having the above advantages according to a simple procedure.